Multivariate Tests

When more than one measure is specified, multivariate tests are computed for the between-subjects and within-subjects factors.

In terms of the study results, you're not really interested in the Gender effect, because even though this effect has a significance value less than 0.05, it simply means that, on average, males and females have different weights and/or triglyceride levels.
You are interested in the TIME effect, because its significance value less than 0.05 means that the weights and/or triglycerides have changed over the course of the diet.
You are also interested in the TIME*GENDER effect, because if significant, it means that the diet has different effects for males and females! However, all four tests have significance values greater than 0.10, so you can safely assume that the diet has similar effects on males and females.

See the contrast results for specifics on time period by time period progress.